Safety-coupling for driving and driven members.



I. H. FRENCH.

SAFETY COUPLING FOR DRIVING AND DRIVEN MEMBERS.

APPLICATION FILED APR. 20,1908.

902,527. Patented 0ct.27, 1908.

UNITED STATES PATENT oFFioE.

FRANK H. FRENCH, OF HOPEDALE. MASSACHUSETTS, ASSIGNOR TO DRAPERCOMPANYfOl' HOPEDALE, MASSACHUSETTS. A CORPORATION OF MAINE.

SAFETY-COUPLING FOR DRIVING AND DRIVEN MEMBERS.

' i I Specification of Letters Patent;

Patented Oct. 27, 1908.

Application filed April 20, 1908. Serial No. 427,996

Hopeda'le, county of Vlorcester. State of Massachusetts, have inventedan Improve-- ment in Safety-Couplings for Driving and Driven Members, ofwhich the following description, in connection with the accompanyingdrawing, is a specification, like let.- ters on the drawing representinglike parts.

This invention has for its object the production of a safety coupling toconnect under normal conditions the driving and driven members of apiece of apparatus, but which will automatically effect theuncoupling ordisconnection of said members when the resistance to the rotation of thedriven member increases beyond a predetermined point. A coupling deviceof this character prevents undue strain or breakage of parts. and isuseful in various forms of apparatus, such for instance as machines forboring wood or metal, wherein any clogging of the tool or an abnormalcut would crease the resistance to its operation.

By means of my invention when the resistance becomes abnormal thedriving member is automatically uncoupled, the coupling being retainedin uncoupled or inoperative position by an automatically acting latchuntil manually released.

The various novel features of my invention will be fully described inthe subjoined specification and particularly pointed out in thefollowing claims.

Figure 1 is a top plan view of the driving and driven portions of apiece of apparatus with one embodiment of my invention applied thereto,the coupling being shown in its operative condition; Fig. 2 is anenlarged detail, principally in section on the line 22, Fig. 1, of thecoupling and adjacent parts.

I have herein chosen to illustrate my invention in connection with aportion of the mechanism of a machlne for boring bobbins, such as formsthe subject-matter of United States Patent No. 828176, granted to BaileyAugust 7, 1906, but it is to be understood that such selection is forillustrative purposes only.

Referring to Fig. 1 the driven member or greatly inshaft 50 has a wormmeshing with a wormgear on a cross-shaft carrying a beveli gear 54meshing with a bevel-gear fast on purpose to be described.

all substantially as in said patent, the devices referred to beingarranged to intermittingly actuate or advance a bobbin-carrier, notherein shown. Hereinthe driving member or shaft 50 has fast upon it apulley 51, to be rotated by a suitable belt, and while in the patentreferred to the pulley is fast on the shaft 50 it will be seen that Ihave cut the shaft in two, the pulley being on the section 50", which isalined with the'main section 50,, which latter is the driven member.

In the present embodiment. of my inven-' tion the driving and drivenshafts are normally connected to rotate in unison by means of a couplingcomprising a sleeve 1 splined at 2 to the driven shaft 50 (see Fig. '2)to rotate therewith w,hile slidable thereon, the sleeve looselyembracing the adjacent end of the driving shaft 5O and having abevelsided or V-shaped notch 3 in its end, to receive a radial lug orpin 4 on the shaft 50. At itsftrot-clted end the coupling sleeve is madecam-shaped, "that----is, ...it has'fuces 5 rising gradually'from'thesides of the notch 3 to the fiat part 6 of the sleeve end, for a Astrong'spring 7 coiled about the shaft 50 bears a ainst the oppositeorunnotched end of the s eeve 1, the spring being adjusted by means of acollar '8 held on the shaft 50 by a set-screw 9, the expansive force'ofthe spring acting normally to maintain the lug 4 in the notch 3, so thatthe rotation of the driving member 50 will rotate the drivenmember 50 inunison therewith under normal conditions. Should the resistance of themember 50 to rotation become abnormal, that. is, above a predetern'iinedpoint, as by some clogging of the mechanism actuated by or from theshaft 50, or for any reason, then the lug 4 will ride up the side of thenotch 3, pressing the sleeve to the right, Fig. 2, the lug after leavingthe notch continuing to press the sleeve toward inoperative positionuntil said lug leaves the incline or cam 5 and rides on the fiat end 6of the sleeve. At vthis time an automatic latch operates and locks thecoupling in inoperative position so that the driving member can continueto rotate without effecting the driven member, until the latch ismanually released.

The sleeve 1 is provided with an elongated slot 10 in which is pivotedat 11 a latch 12 the shaft 31 carrying an arm 30 and disk 33, having aninturned too 13, Fig. 2, pressed against the shaft '50-by a suitablespring 14,. as shown in Fig. 2, the shaft being provided intoinoperative position the toe of the latch is thrown Into the recess 15by the latch-spring l L, so that the sleeve is retained in itsinoperative position, leaving the lug 4 free to rotate with the shaft 50past the adjacent end of the sleeve without interference and until themachine is stopped.

The coupling provides a'safety connection between the driving and drivenmembers of the apparatus, and when the fault has been corrected theoperator presses down the spring-engaged end of the latch, releasing itstoe from the recess 15, unlocking the sleeve and permitting .the spring7 to expand, so that when the shaft 50 -by rotation brings the h1g4opposite the notch 3 the coupling will automatically re-connect thedriving and driven members.

My invention may be used with various forms of apparatus, as will bemanifest, and may be changed or-modified in various details withoutdeparting from-the spirit and scope of my invention as set forth in theappended claims.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is 1. The combination, with driving and drivenshafts, of a coupling normally connecting them to rotate in unison, saidcoupling comprising a sleeve rotatable with and longitudinally movableupon the driven shaft and-having a beveled notch, a lug on the drivingshaft to enter the notch, a spring to nornecting them to rotate inunison, said coupling comprising a sleeve rotatable with andlongitudinally movable upon the driven shaft and having one endcam-shaped and provided with a V-shaped notch at the low part of the camend, a lugon the driving shaft to enter said notch, a spring to normallymaintain the'lug in the notch to thereby couple the shafts to rotatetogether, resistance to rotation of the driven shaft when greater thanthe action of the spring causing the lug to ride u out of the notch andonto the high part 0 the cam-end of the sleeve, moving the latter intoinoperative position, and a springactuated latch carried by the sleeveto automatically engage the driven shaft and retain the sleeveinoperative when so positioned.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

FRANK H. FRENCH.

Witnesses ALBERT W. EDWARDS, EDWARD DANA Oseoon.

